Diamond bonded construction with reattached diamond body

ABSTRACT

Diamond bonded construction comprise a diamond body attached to a support. In one embodiment, an initial substrate used to sinter the body is interposed between the body and support, and is thinned to less than 5 times the body thickness, or to less than the body thickness, prior to attachment to the support to relieve stress in the body. In another embodiment, the substrate is removed after sintering, and the body is attached to the support. The support has a material construction different from that of the initial substrate, wherein the initial substrate is selected for infiltration and the support for end use properties. The substrate and support include a hard material with a volume content that may be the same or different. Interfaces between the body, substrate, and/or support may be nonplanar. The body may be thermally stable, and may include a replacement material disposed therein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. application Ser. No.12/903,081, filed Oct. 12, 2010, now U.S. Pat. No. 8,925,656, issuedJan. 6, 2015, which claims priority to U.S. Provisional PatentApplication 61/250,813, filed on Oct. 12, 2009, which applications areherein incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to diamond bonded constructions and,more particularly, to diamond bonded constructions that are speciallyengineered with a diamond body that is attached to a substrate otherthan the one used for sintering the diamond body at high pressure/hightemperature conditions to provide improved performance properties andservice life when compared to conventional diamond bonded constructions.

2. Background of the Invention

The use of constructions comprising a body formed from ultra-hardmaterials such as diamond, polycrystalline diamond (PCD), cubic boronnitride (cBN), polycrystalline cubic boron nitride (PcBN) are well knownin the art. An example of such constructions may be found in the form ofcutting elements comprising an ultra-hard component or body that isjoined to a metallic component or substrate. In such cutting elements,the wear or cutting portion is formed from the ultra-hard component andthe metallic portion is provided for the purpose of attaching thecutting element to a desired wear and/or cutting device. In such knownconstructions, the ultra-hard component may be formed from thoseultra-hard materials described above that provide a high level of wearand/or abrasion resistance that is greater than that of the metalliccomponent.

The use of PCD as an ultra-hard material for forming such constructionsis well known in the art. PCD is formed by subjecting a volume ofdiamond grains to high pressure/high temperature (HPHT) conditions inthe presence of a suitable catalyst material, such as a solvent catalystmetal selected from Group VIII of the Periodic table. Oftentimes, thesource of the solvent catalyst material used to form PCD is thesubstrate, wherein the solvent catalyst material is present as aconstituent of the substrate that migrates therefrom and infiltratesinto the adjacent diamond body during HPHT processing. The resultingconstruction is a PCD compact comprising the PCD body joined to thesubstrate.

An issue known to exist with such conventional PCD compact constructionsis the existence of residual stress within diamond body adjacent theregion interfacing with the substrate that is created during HPHTprocessing. Such residual stress may cause cracking within the diamondbody when the compact is placed in a wear or cutting operation that mayresult in premature compact failure. Additionally, while the substratesused to make such conventional PCD compact constructions may haveproperties desired to facilitate sintering of the diamond body duringHPHT processing, e.g., properties associated with solvent catalyst metalcontent and/or type, such substrates may not have the most desiredproperties for the ultimate use of the compact in a wear or cuttingoperation, e.g., may not have a desired degree of erosion resistance,thereby possibly limiting the effective service life of the compact.

It is, therefore, desirable that diamond bonded constructions beconstructed in a manner that provides a reduced or eliminated degree ofresidual stress when compared to conventional PCD compact constructions.It is also desired that such diamond body constructions be constructedin a manner comprising a substrate having improved end-use serviceproperties when compared to conventional PCD compact constructions. Itis further desired that such diamond bonded constructions provide theseimproved properties without sacrificing desired properties of wearresistance, abrasion resistance, impact resistance, and fracturetoughness when compared to conventional PCD compact constructions. It isstill further desired that such diamond bonded constructions be producedin a manner that is efficient and does not involve the use of exoticmaterials and/or techniques.

SUMMARY OF THE INVENTION

Diamond bonded constructions prepared according to principles of theinvention comprise a sintered diamond body that is attached to a finalsubstrate or support. The diamond body is sintered under HPHT conditionsand comprises a matrix phase of intercrystalline bonded diamond, and aplurality of interstitial regions dispersed within the matrix phase. Aninitial substrate may be used as a source of a catalyst material forsintering and/or the catalyst material may be provided in powder formand mixed with the diamond powder prior to sintering.

If an initial substrate is used, in one example embodiment it may remainattached to the diamond body after sintering, and is thinned a desiredamount to reduce residual stress within the diamond body. In suchexample embodiment, a final substrate or support is attached to theremaining portion of the initial substrate to form the diamond bondedconstruction. In an example embodiment it is desired that the thicknessof the remaining portion of the initial substrate be less than about 5times that of the diamond body, and more preferably be less than thethickness of the diamond body.

In a second example embodiment, the initial substrate is completelyremoved from the diamond body, and the diamond body is subsequentlyattached to the support to form the diamond bonded constructions.

In both embodiments, it is desired that the support have a materialcomposition that is different than that of the initial substrate. Thesupport and initial substrate may comprise the same hard material. Thesupport may have a volume content of hard material that is the same asor different from the volume content of the hard material in thesubstrate before sintering the diamond body by HPHT process. The diamondbonded construction may comprise a planar or nonplanar interface betweenthe diamond body and initial or final substrate, and /or a planar ornonplanar interface between the remaining substrate portion and thesupport or support as needed to provide a desired degree of attachmentstrength within the construction.

Diamond bonded constructions of this invention may comprise a diamondbody that has been treated to render part of or the entire diamond bodythermally stable or substantially free of the catalyst material used toform the same. All or a portion of the thermally stable region mayinclude a replacement material disposed therein.

Diamond bonded constructions of this invention have a reduced amount ofresidual stress when compared to conventional PCD constructions, therebyenhancing the operating life of such constructions. Additionally, theability to provide a construction having a final substrate or supportthat is different from the initial substrate enables the tailoring ofthe construction to provide desired infiltration characteristics duringdiamond body formation, while at the same time providing superior finalsubstrate properties to meet particular end-use applications, therebyfurther operating to improve effective service life.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will beappreciated as the same becomes better understood by reference to thefollowing detailed description when considered in connection with theaccompanying drawings wherein:

FIG. 1 is a cross sectional side view of a diamond bonded bodycomprising an initial substrate attached thereto that was used to sinterthe diamond bonded body during HPHT processing;

FIG. 2 is a cross sectional side view of a diamond bonded body;

FIG. 3 is a cross sectional side view of an example embodiment diamondbonded construction comprising a diamond bonded body attached toremaining portion of the initial substrate used to sinter the diamondbody, wherein the initial substrate is attached to a final substrate;

FIG. 4 is a cross sectional side view of an example embodiment diamondbonded construction comprising a diamond bonded body that is attached toa final substrate;

FIG. 5 is a perspective side view of a shear cutter comprising thediamond bonded construction;

FIG. 6 is a perspective side view of a drag bit comprising a number ofthe shear cutters of FIG. 5;

FIG. 7 is a perspective side view of an insert comprising the diamondbonded construction;

FIG. 8 is a perspective side view of a rotary cone drill bit comprisinga number of the inserts of FIG. 7; and

FIG. 9 is a perspective side view of a percussion or hammer bitcomprising a number of the inserts of FIG. 8.

DETAILED DESCRIPTION

Diamond bonded constructions of this invention comprise a diamond bondedbody formed from polycrystalline diamond (PCD). The diamond bonded bodymay include a region of thermally stable polycrystalline diamond (TSP),wherein such region may or may not comprise an infiltrant material. Inone embodiment, a substrate used to initially sinter the diamond bondedbody is removed therefrom, and a different final substrate is attachedto the diamond body. In another embodiment, the substrate used toinitially sinter the diamond body remains attached thereto and isthinned a desired amount before being attached to a different finalsubstrate or support In such example embodiments, the final substratediffers from the initial substrate in its material composition.

While the body has been described above as a diamond bonded body, it isto be understood that the body may be formed ultra-hard materials otherthan diamond. As used herein, the term “ultra-hard” is understood torefer to those materials known in the art to have a grain hardness ofabout 4,000 HV or greater. Such ultra-hard materials may include thosecapable of demonstrating physical stability at temperatures above about750° C., and for certain applications above about 1,000° C., that areformed from consolidated materials. Such ultra-hard materials mayinclude but are not limited to diamond, cubic boron nitride (cBN),diamond-like carbon, boron suboxide, aluminum manganese boride, andother materials in the boron-nitrogen-carbon phase diagram which haveshown hardness values similar to cBN and other ceramic materials.

PCD is an ultra-hard material formed in the manner noted above bysubjecting a volume of diamond grains to HPHT conditions in the presenceof a catalyst material. The catalyst material may be a solvent catalystmetal, such as one or more selected from Group VIII of the Periodictable. As used herein, the term “catalyst material” refers to thematerial that was initially used to facilitate diamond-to-diamondbonding or sintering at the initial HPHT conditions used to form thePCD. PCD has a material microstructure comprising a matrix phase ofintercrystalline bonded diamond, and a plurality of interstitial regionsdispersed within the matrix phase, wherein the catalyst material isdisposed within the interstitial regions.

TSP is formed by removing the catalyst material from PCD, so that theremaining diamond structure is substantially free of the catalystmaterial. TSP has a material microstructure characterized by a matrixphase of intercrystalline bonded diamond, and a plurality of emptyinterstitial regions. If desired, the empty interstitial regions may befilled with a desired replacement or infiltrant material as describedbelow. Alternatively, TSP may comprise the catalyst material that hasbeen treated to prevent it from acting in a catalytic manner when thediamond body is subjected to high temperature conditions.

Diamond grains useful for forming the diamond bonded body may includenatural and/or synthetic diamond powders having an average diametergrain size in the range of from submicrometer in size to 100micrometers, and more preferably in the range of from about 1 to 80micrometers. The diamond powder may contain grains having a mono ormulti-modal size distribution. In an example embodiment, the diamondpowder has an average particle grain size of approximately 20micrometers. In the event that diamond powders are used havingdifferently sized grains, the diamond grains are mixed together byconventional process, such as by ball or attritor milling for as muchtime as necessary to ensure good uniform distribution.

The diamond grain powder is preferably cleaned, to enhance thesinterability of the powder by treatment at high temperature, in avacuum or reducing atmosphere. The diamond powder mixture is loaded intoa desired container for placement within a suitable HPHT consolidationand sintering device.

During the HPHT process, a catalyst material, e.g., a solvent metalcatalyst or the like, is combined with the diamond powder. In apreferred embodiment, the catalyst material is provided by infiltrationfrom a desired substrate that is positioned adjacent the diamond powderprior to HPHT processing and that includes the catalyst material as aconstituent material. Suitable substrates useful for as a source forinfiltrating the catalyst material may include those used to formconventional PCD materials, and may be provided in powder, green stateand/or already sintered form. A feature of such substrate is that itincludes a metal solvent catalyst that is capable of melting andinfiltrating into the adjacent volume of the diamond powder tofacilitate bonding the diamond grains together during the HPHT process.In an example embodiment, the catalyst material is Co, and a substrateuseful for providing the same is a cobalt containing substrate, such asWC-Co.

Alternatively, the diamond powder may be provided in the form of agreen-state part or mixture comprising diamond powder that is combinedwith a binding agent to provide a conformable material product, e.g., inthe form of diamond tape or other formable/conformable diamond mixtureproduct to facilitate the manufacturing process. In the event that thediamond powder is provided in the form of such a green-state part, it isdesirable that a preheating step take place before HPHT consolidationand sintering to drive off the binder material. In an exampleembodiment, the PCD material resulting from the above-described HPHTprocess may have diamond volume content in the range of from about 85 to95 percent.

The diamond powder or green-state part is loaded into a desiredcontainer for placement within a suitable HPHT consolidation andsintering device. The HPHT device is activated to subject the containerto a desired HPHT condition to effect consolidation and sintering of thediamond powder. In an example embodiment, the device is controlled sothat the container is subjected to a HPHT process having a pressure of5,000 MPa or greater and a temperature of from about 1,350° C. to 1,500°C. for a predetermined period of time. At this pressure and temperature,the catalyst material melts and infiltrates into the diamond powdermixture, thereby sintering the diamond grains to form PCD. After theHPHT process is completed, the container is removed from the HPHTdevice, and the so-formed PCD part is removed from the container.

FIG. 1 illustrates a PCD construction 10 prepared in the mannerdescribed above comprising a PCD body 12 that is attached to an initialor infiltration substrate 14 during HPHT processing. The initialsubstrate 14 is selected for the purpose of introducing a desiredcatalyst material into the diamond volume during the HPHT process tofacilitate desired sintering. An interface surface 16 between the PCDbody 12 and the initial substrate 14 may be planar or nonplanar.

The PCD body 12 includes top and side surfaces 18 and 20 that may or maynot be working surfaces. If desired, the PCD body 12 may have a bevelededge running between the top and side surfaces. The PCD body may beconfigured having a desired form for a particular end-use applicationwithout any further shaping or sizing. Alternatively, the PCD body mayinitially be configured having a form that facilitates HPHT processing,and then be subsequently shaped or sized as desired for use in theend-use application.

FIG. 2 illustrates a PCD body 22 without an initial or infiltrantsubstrate attached thereto. The infiltration substrate that was used toform the PCD body (as illustrated in FIG. 1), is removed from the PCDbody after sintering for the purpose of joining the body to a desiredfinal substrate or support. The PCD body 22 may include the samesurfaces noted above 24 and 26, and may have a planar or nonplanarsubstrate interface surface 28.

FIG. 3 illustrates a example embodiment diamond bonded construction 30comprising a diamond bonded body 32 that is attached to remainingportion 34 of an initial substrate used to sinter the diamond bondedbody. This construction may be formed by taking the PCD constructionillustrated in FIG. 1, and removing a desired thickness of the initialsubstrate 34 therefrom by conventional machining process or the like. Inan example embodiment, the remaining initial substrate 34 is thinned inan amount that operates to relieve the residual stress existing in thediamond body from the sintering process a desired amount.

In such example embodiment, the remaining initial substrate portion 34has a thickness that is less than about five times the thickness of thediamond bonded body 32, and in a preferred embodiment has a thicknessthat is less than that of the diamond bonded body 32. A remaininginitial substrate portion 34 having a thickness that is greater thanthat of the diamond bonded body may not provide the degree of residualstress relief in the diamond bonded body that is desired for aparticular end-use application. Ideally, in this example embodiment, itis desired that the amount of the initial substrate removed or thinnedbe an amount that is effective in providing a desired degree of residualstress relief in the diamond body. Removing more than this amount maynot be desired as it adds to the cost of manufacturing and/orcontributes to the unwanted waste of materials.

Referring still to FIG. 3, the construction 30 further comprises a finalsubstrate or support 36 that is attached or otherwise joined to theremaining portion 34. An interface surface 38 between the finalsubstrate 36 and the remaining portion 34 may be planar or nonplanardepending on the particular end-use application. In an end-useapplication calling for a high degree of delamination resistance, anonplanar interface may be desired to provide an enhanced degree ofattachment strength between the final substrate and the remaininginitial substrate portion. A construction comprising both a nonplanarinterface between the diamond body and the initial substrate remainingportion, and the initial substrate and the final substrate may provide afurther degree of enhanced resistance against unwanted delaminationduring use.

In an example embodiment, the final substrate 36 has a materialcomposition and/or one or more performance properties that are differentfrom that of an infiltration substrate used to form the diamond bondedbody. Materials useful for forming the final substrate in suchconstructions include those useful for forming infiltrant substrates formaking conventional PCD materials, such a metallic materials, ceramicmaterials, cermet materials, and combinations thereof. Example finalsubstrates may be formed from hard materials like carbides such as WC,W₂C, TiC, VC, or ultra-hard materials such as synthetic diamond, naturaldiamond and the like, wherein the hard or ultra-hard materials mayinclude a softer binder phase comprising one or more Group VIII materialsuch as Co, Ni, Fe, and Cu, and combinations thereof

In an example embodiment, the final substrate may have one or morematerial properties making it relatively better suited for use of theconstruction in an end-use application than the infiltration substrateused to initially form the diamond bonded body. For example, the finalsubstrate may have a material composition comprising a lesser amount ofa binder material, such as a Group VIII material or the like, than thatof the infiltrant substrate, making it less well suited for infiltrationand sintering purposes, but providing an improved degree of erosionresistance and thus making it better suited for end-use purposes thatare exposed to erosive conditions.

In an example embodiment, the PCD construction may be formed using aWC-Co initial substrate having a WC hard material with a particle sizeof about 3 microns and having a Co content of about 14 percent by weightprior to sintering of the diamond body. The final substrate may have thesame WC particle size but a Co content of about 11 percent by weight.Such an initial substrate includes a Co content that facilitatesinfiltration and sintering during HPHT processing, while such a finalsubstrate has a reduced Co content that provides a desired improvementin erosion resistance to facilitate end use. It is understood that thisdescription is representative of only one example construction, and thatinitial and final substrates having constructions and/or propertiesother than those described may be used to form diamond bondedconstructions.

FIG. 4 illustrates an example embodiment diamond bonded construction 40comprising a diamond bonded body 42 that is attached to a finalsubstrate 44. Unlike the construction embodiment illustrated in FIG. 3,the diamond bonded construction of FIG. 4 does not include a remaininginitial substrate portion. In an example embodiment, any initialsubstrate that was used to sinter the diamond bonded body during HPHTprocessing is removed, and the resulting diamond bonded body is attachedto the final substrate 44. The final substrate may be formed from thesame types of materials described above. In this example embodiment, thediamond bonded body is formed using an initial substrate (as illustratedin FIG. 1) as the source of the catalyst material for infiltration, andthe infiltrant substrate is subsequently removed from the so-formeddiamond bonded body by conventional method and prepared for attachmentwith the final substrate. The initial and final substrates may be thesame as those described above for the embodiment illustrated in FIG. 3.

The final substrate may be attached to the diamond bonded body, in oneembodiment, or to a remaining portion of an initial substrate, inanother embodiment, by conventional techniques such as by diffusionbonding, brazing, or mechanical locking under HPHT conditions or otherappropriate conditions and/or environment. In a preferred embodiment,the final substrate is attached to the diamond bonded body or remaininginitial substrate portion by HPHT process to ensure robust bonding andno conversion of diamond into graphite.

If desired, the diamond bonded body may be treated to remove at least aportion of the catalyst material disposed therein, thereby providing aresulting diamond body having improved properties of thermal stability.The particular end-use application will influence the extent andlocation of catalyst material removed from the diamond bonded body. Theterm “removed”, as used with reference to the catalyst material isunderstood to mean that a substantial portion of the catalyst materialno longer resides within the treated region of the diamond body.However, it is to be understood that some small amount of catalystmaterial may still remain in the part, e.g., within the interstitialregions and/or adhered to the surface of the diamond crystals.Additionally, the term “substantially free”, as used herein to refer tothe catalyst material in the treated region of the diamond body, isunderstood to mean that there may still be some small/trace amount ofcatalyst material remaining within the treated diamond body as notedabove.

In an example embodiment, the diamond bonded body may be treated toremove catalyst material by chemical treatment, such as by acid leachingor aqua regia bath, electrochemical treatment such as by electrolyticprocess, by liquid metal solubility, or by liquid metal infiltrationthat sweeps the existing catalyst material away and replaces it withanother noncatalyst material during a liquid phase sintering process, orby combinations thereof. In an example embodiment, the catalyst materialis removed from the diamond body by an acid leaching technique, such asthat disclosed for example in U.S. Pat. No. 4,224,380. Acceleratedcatalyst removal techniques may be used that involved elevatedtemperature and/or elevated pressure and/or sonic energy and the like.The diamond bonded body may be subjected to such treatment before orafter it is attached to the final substrate.

The treated region of the diamond bonded body comprises a materialmicrostructure having a polycrystalline diamond matrix phase made up ofa plurality of diamond grains or crystals that are bonded together, anda plurality of interstitial regions that are disposed between the matrixphase of bonded together diamond grains, and that exist as empty poresor voids within the material microstructure, as a result of the catalystmaterial being removed therefrom.

In an example embodiment, only a partial region of the diamond body istreated and the treated region extends a desired depth from a surface,which may be a working surface or the bonding surface to the substrate,of the diamond bonded body. In an example embodiment, the depth of suchtreated region may be about 0.05 mm or less, or may be about 0.05 to 0.4mm. The exact depth of the treated region will depend on the bondingprocess and/or end-use application.

If desired, the treated region of the diamond bonded body may be furthertreated so that all or a population of the interstitial regions withinthe part, previously empty by virtue of removing the catalyst materialtherefrom, are filled with a desired replacement or infiltrant material.In an example embodiment, such region may be filled, backfilled orreinfiltrated with a material that operates to minimize and/or eliminateunwanted infiltration of material from the final substrate, and/or thatoperates to improve one or more properties of the diamond bonded body.

Example replacement or infiltrant materials useful for treating thediamond bonded body may include materials selected from the groupincluding metals, metal alloys, metal carbonates, carbide formers, i.e.,materials useful for forming a carbide reaction product with the diamondin the body, and combinations thereof. Example metals and metal alloysinclude those selected from Group VIII of the Periodic table, examplescarbide formers include those comprising Si, Ti, B, and others known toproduce a carbide reaction product when combined with diamond at HPHTconditions. The infiltrant material preferably has a melting temperaturethat is within the diamond stable HPHT window, and may be provided inthe form of a powder layer, a green state part, an already sinteredpart, or a preformed film. The diamond bonded body may be infiltratedduring or independently of the process used to attach the diamond bondedbody to the final substrate.

It is to be understood that the material selected to form the infiltrantmaterial may permit some degree of substrate constituent infiltrationtherein, possibly in a sufficient degree to form a desired attachmentbond between the diamond bonded body and the final substrate, e.g.,during an HPHT attachment process. If desired, the extent of backfillingor infiltrating the diamond bonded body may be controlled to leave aportion of the treated diamond bonded body uninfiltrated. This mayeither be done, for example, by careful control of the infiltrationprocess or may be done after the diamond bonded body has been completelyinfiltrated by further treating the infiltrated region of the diamondbonded body to remove the infiltrant from a targeted region. Forexample, it may be desired that a surface portion of the diamond bondedbody, and possibly a region extending from such surface, not include theinfiltrant material for the purpose of providing a desired level ofthermal stability, abrasion and/or wear resistance. In an exampleembodiment, such a surface portion of the diamond bonded body may form asurface portion, such as a working surface, of the final diamond bondedconstruction.

A feature of diamond bonded constructions of this invention is that theyhave reduced amount of residual stress when compared to conventional PCDconstructions that are formed by using and that remain attached to asintering substrate without further processing. Such reduction inresidual stress operates to enhance the operating life of suchconstructions. Additionally, such diamond bonded constructions may beconfigured having an additional nonplanar interface, e.g., between theinitial and final substrates, that operates to provide an improveddegree of delamination resistance, further operating to enhanceeffective service life. Still further, such diamond bonded constructionsinclude a final substrate that differs from a substrate used as acatalyst material infiltrant source during sintering of the diamondbody. In a preferred embodiment, the final substrate is selected toprovide improved end-use properties, such as erosion resistance in thelike, when compared to conventional PCD constructions comprising only aninfiltration substrate, thereby operating to improve effective servicelife.

Diamond bonded constructions of this invention may be used in a numberof different applications, such as tools for mining, cutting, machining,milling and construction applications, wherein properties of shearstrength, thermal stability, wear and abrasion resistance, mechanicalstrength, and/or reduced thermal residual stress are highly desired.Constructions of this invention are particularly well suited for formingworking, wear and/or cutting elements in machine tools and drill andmining bits such as roller cone rock bits, percussion or hammer bits,diamond bits, and cutting elements such as inserts, shear cutters andthe like used in subterranean drilling applications.

FIG. 5 illustrates a diamond bonded construction embodied in the form ofa shear cutter 50 used, for example, with a drag bit for drillingsubterranean formations. The shear cutter 50 comprises a diamond bondedbody 54 as described above. The diamond bonded body is attached to acutter/final substrate 52. The diamond bonded body 54 includes a workingor cutting surface 56. The cutter substrate may include a portion of aninitial substrate and a final substrate or may comprise only a finalsubstrate.

Although the shear cutter in FIG. 5 is illustrated having a generallycylindrical configuration with a flat working surface that is disposedperpendicular to an axis running through the shear cutter, it is to beunderstood that shear cutters formed from diamond bonded constructionsmay be configured other than as illustrated and such alternativeconfigurations are understood to be within the scope of this invention.

FIG. 6 illustrates a drag bit 60 comprising a plurality of the shearcutters 62 described above and illustrated in FIG. 5. The shear cuttersare each attached to blades 64 that each extend from a head 66 of thedrag bit for cutting against the subterranean formation being drilled.

FIG. 7 illustrates an embodiment of a diamond bonded construction in theform of an insert 70 used in a wear or cutting application in a rollercone drill bit or percussion or hammer drill bit used for subterraneandrilling. For example, such inserts 70 may be formed from blankscomprising a substrate 72 formed from one or more of the initial and/orfinal substrate materials 73 disclosed above, and a diamond bonded body74 having a working surface 76. The insert substrate may include aportion of an initial substrate and a final substrate or may compriseonly a final substrate. The blanks are pressed or machined to thedesired shape of a roller cone rock bit insert.

Although the insert in FIG. 7 is illustrated having a generallycylindrical configuration with a rounded or radiused working surface, itis to be understood that inserts formed from diamond bondedconstructions configured other than as illustrated and such alternativeconfigurations are understood to be within the scope of this invention.

FIG. 8 illustrates a rotary or roller cone drill bit in the form of arock bit 78 comprising a number of the wear or cutting inserts 70disclosed above and illustrated in FIG. 7. The rock bit 78 comprises abody 80 having three legs 82, and a roller cutter cone 84 mounted on alower end of each leg. The inserts 70 may be fabricated according to themethod described above. The inserts 70 are provided in the surfaces ofeach cutter cone 84 for bearing on a rock formation being drilled.

FIG. 9 illustrates the inserts 70 described above as used with apercussion or hammer bit 86. The hammer bit comprises a hollow steelbody 88 having a threaded pin 90 on an end of the body for assemblingthe bit onto a drill string (not shown) for drilling oil wells and thelike. A plurality of the inserts 70 is provided in the surface of a head92 of the body 88 for bearing on the subterranean formation beingdrilled.

Other modifications and variations of diamond bonded constructions andmethods of forming the same according to the principles of thisinvention will be apparent to those skilled in the art. It is,therefore, to be understood that within the scope of the appendedclaims, this invention may be practiced otherwise than as specificallydescribed.

What is claimed:
 1. A diamond bonded construction comprising: a diamondbody comprising a matrix phase of intercrystalline bonded diamond and aplurality of interstitial regions dispersed within the matrix phase,wherein the interstitial regions are substantially free of a catalystmaterial used to sinter the diamond body at high pressure-hightemperature conditions; and a support joined to the diamond body andcomprising a constituent that has infiltrated from the support into aregion of the diamond body to fill a population of the interstitialregions.
 2. The diamond bonded construction as recited in claim 1wherein the support comprises a material selected from the groupconsisting of synthetic diamond, natural diamond, WC, W₂C, TiC, VC, Co,Ni, Fe, Cu, Group VIII materials, and combinations thereof
 3. Thediamond bonded construction as recited in claim 2 wherein the supportcomprises synthetic diamond or natural diamond.
 4. The diamond bondedconstruction as recited in claim 1 wherein the diamond body comprises afirst region adjacent a top surface of the diamond body, and a secondregion adjacent the substrate, wherein the interstitial regions in thefirst region are substantially empty.
 5. The diamond bonded constructionas recited in claim 4 wherein the interstitial regions in the diamondbody second region contain a constituent of the support.
 6. The diamondbonded construction as recited in claim 5 wherein the constituentdisposed within the interstitial regions in the diamond body secondregion comprises diamond.
 7. A bit for drilling subterranean formationscomprising a body and a number of cutting elements operatively attachedthereto, wherein one or more of the cutting elements comprises thediamond bonded construction of claim
 1. 8. A diamond bonded constructioncomprising: a diamond body comprising a matrix phase of intercrystallinebonded diamond and a plurality of interstitial regions dispersed withinthe matrix phase, wherein interstitial regions are substantially free ofa catalyst material used to sinter the diamond body at highpressure-high temperature conditions; and a support joined to thediamond body and comprising synthetic or natural diamond as combinedwith a material selected from the group consisting of WC, W₂C, TiC, VC,Co, Ni, Fe, Cu, Group VIII materials, and combinations thereof.
 9. Thediamond bonded construction as recited in claim 8 wherein a populationof the interstitial regions is filled with an infiltrant material. 10.The diamond bonded construction as recited in claim 9 wherein theinfiltrant material is a constituent of the support.
 11. The diamondbonded construction as recited in claim 10 wherein the infiltrantmaterial comprises diamond.
 12. The diamond bonded construction asrecited in claim 11 wherein the population of interstitial regionsfilled with the infiltrant material extends within the diamond body froma surface of the diamond body in contact with the support.
 13. Thediamond bonded construction as recited in claim 9 wherein the diamondbody comprises a first region comprising interstitial regions that areempty and disposed adjacent a diamond body top surface, and a secondregion comprising the interstitial regions filled with the infiltrantmaterial and disposed adjacent the support.
 14. A bit for drillingsubterranean formations comprising a body and a number of cuttingelements operatively attached thereto, wherein one or more of thecutting elements comprises the diamond bonded construction of claim 8.15. A diamond bonded construction comprising: a diamond body comprisinga matrix phase of intercrystalline bonded diamond and a plurality ofinterstitial regions dispersed within the matrix phase, wherein theinterstitial regions are substantially free of a catalyst material usedto sinter the diamond body at high pressure-high temperature conditions;and a support joined to the diamond body formed from a material selectedfrom the group consisting of synthetic diamond, natural diamond, WC,W₂C, TiC, VC, Co, Ni, Fe, Cu, Group VIII materials, and combinationthereof; wherein the diamond body comprises a first region withinterstitial regions that are substantially empty and a second regionthat includes an infiltrant material.
 16. The diamond bondedconstruction as recited in claim 10 wherein the infiltrant material isdiamond.
 17. The diamond bonded construction as recited in claim 10wherein the support comprises synthetic or natural diamond.
 18. Thediamond bonded construction as recited in claim 10 wherein the secondregion is adjacent the support and the first region is adjacent a topsurface of the diamond body.
 19. The diamond bonded construction asrecited in claim 15 wherein an interface between the diamond body andthe support is nonplanar.
 20. A bit for drilling subterranean formationscomprising a body and a number of cutting elements operatively attachedthereto, wherein one or more of the cutting elements comprises thediamond bonded construction of claim 15.